Tubular heater for the air for combustion of steam locomotives



H. BOLTSHAUSER. TUBULARHEATERFORTHEAIRFOR'COMBUSTION OFSTEAMLOGOMOTIVES.

APPLiCATION FILED MAR 3h I92].

Patented Dec; 5,

Patented Dec. 5, 1922.

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HEINRICH BOLTSHAUSER, 0F ZURICH, SWITZERLAND.

TUBULAR HEATER FOR THE AIR FOR COMBUSTION OF STEAM LOCOMOTIVES.

Application filed March 31, 1921. Serial No. 457,351.

(GRANTED UNDER THE PROVISIONS OF THE ACT OF MARCH 3, 1921, 41 STAT. I, 1313;)

To all 1072077? it may concern:

Be it known that I, HEINRICH BOLTSHAU- em, a citizen of the Republic of Switzerland, residing at Zurich, Switzerland, have invented certain new and useful Improvements in Tubular Heaters for the Air for Combustion of Steam Locomotives (for which I have filed applications for patents in. Switzerland December 15, 1919 (Patent No. 86,503) Germany December 18, 1919; France November 22, 1920; and Belgium November 23, 1920); and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, ref erence being had to the accompanying drawing, and to letters or figures of reference marked thereon, which form a part of this specification.

The present invention relates to improvements in a tubular heater for the air for combustion of steamlocomotive, said heater being mounted laterally of the smoke box and being heated by the waste gas of the boiler furnace.

In the hitherto proposed tubular heaters or economizers the air to be heated is forced through a nest of tubes with which come in contact the waste gases of the boiler furnace compelled to pass on their way towards the funnel through said tubes. These tube heaters present the drawbacks that the free passage area for the air is relatively small, that the air during its admission is con tracted and consequently there-is a considerable drop of pressure so that a very large nest of tubes is required inorder to cause, when no powerful fan is used, a sufficient quantity of air to pass through the heater. iX loreover, in the heaters hitherto proposed it is practically nearly impossible to clean. the outer wall of the tubes Within a sufficient short time and. consequently to remove often enough the flue dust from said walls.

The object of the present invention is to provide a tubular heater for the air for combustion. of steam locomotives in which the drawbacks referred to are eliminated. According to this invention at least one nest of tubes is provided which is arranged laterally of the steam boiler and surrounds in a shell-like manner a portion ofthe latter.

This nest of tubes guides the flue gases from the smoke box of the locomotive towards a second funnel, whilst the casing surrounding the nest of tubes ends at its forward end in a flaring admission opening for the air for combustion. Thus, the cross-sectional area for the passage of the air present between the tubes is great and consequently the air does not produce so great contractions as is the case when it is compelled to pass through each single tube. The novel heater presents the further advantage that the flue dust deposits within the tubes from where it may be easily blown out.

The invention is described hereinafter in detail with reference to the accompanying drawing which shows diagrammatically by way, of example a constructional example of the tube heater.

Fig. 1 is partly aside elevation and partly I front view of the locomotiveseen from C,

and Fig. 4 is a horizontal section on the line (3-D of Fig. 1 through a portion of the smoke box and the admission end of the tube heater or economizer. I

In order to further utilize the heat contained in the flue gases leaving the smoke tubes 1, said gases are turned off by 180 in the direction ofthe'ar1'ows3 (Fig. 4E) and are compelled to flow into tubes 5. "The latter communicate at their front end with'the space 6 situated immediately below the smoke box 2 and-at their rear end with a chamber 7, the upper end of whichforms a second funnel 8. The gasesIflow-through this funnel 8 in the direct-ion of the arrow 9 directly into the atmosphere. The fresh air streaming in the direction of the arrows From the rear end of the casing 12 the air passes through a branch 13 into a fan 14 main driven by a small steam turbine 15. Even when the branch 13 would not be connected to the fan 1% but to a large receptacle, or if it would end within the furnace chamber, a current of air would already be generated within the chamber 12 solely in consequence of the travelling speed of the locomotive. This draught is now increased Whilst the 10- comotive is moving by the fan 14 exerting a sucking action. The fan 14 forces the air through pipe not shown in the drawing into the furnace chamber where a pressure above that of the atmosphere is produced, so that the combustion gases are forced through the heating tubes 1, smoke box 2, smoke tubes 5, collecting chamber 7 and funnel 8. Whilst the air is streaming through the casing 12 it receives heat from the flue gases flowing through the pipes 5 from the front end to the rear end of the latter. This heat taken up is conveyed by the air to the firing place or furnace chamber, increasing thereby the efficiency of the locomotive. Owing to the action exerted by the fan 14, also an artificial draught and a transmission of heat from the flue gases to the fresh air entering at 10 can beobtained, and this even when the locomotive is stationar, i. e. for instance at the beginning of the heating of the locomotive or during a stop at a station. The lateral. arrangement of the casing 11 on the steam boiler protects the latter from a too great radiation of heat. The heat passing from the inside of the boiler into the interior of the casing 12 is transmitted for a useful purpose to the air for combustion.

It is evident, that also more than one tubular heater of the described kind can be provided on the locomotive when required.

I claim:

1. A tubular air preheater for locomotives, comprising a casing extending along the locomotive boiler andsurrounding in a shell-like manner a portion of said boiler and having an enlarged funnel-like entrance opening for the air to be pre-heated, a nest of tubes through which combustion gases pass arranged within said casing, the flue gases passing through the tubes effecting a heating of the air streaming along the outside of the tubes, and means for drawing the fresh air through said casing and for forcing the heated air into the furnace to produce therein a pressure above atmospheric: pressure.

2. A tubular air pre-heater for locomotives, comprising casing extending along the locomotive boiler and having an enlarged funnel-like entrance opening for the air to be pre-heated, a nest of tubes through which combustion gases pass heating the air contacting with the outside thereof, and a suc tion and forcing fan arranged between the discharge end of said casing and a fire box of the locomotive for drawing the air from and through said casing and producing a forced draft for the locomotive.

3. A tubular air pre-heater for locomotives, comprising a casing extending along the locomotive boiler and having an enlarged funnel-like entrance end, a nest of tubes in said casing and arranged to receive combustion gases from the locomotive smoke box and discharge them at the opposite end, and a suction and forcing fan arranged between the discharge end of said casing and the locomotive fire box for drawing heated air from said casing and producing forced draft.

4. A tubular air preheater for locomotives, comprising a casing, extending along the locomotive boiler and surrounding in a shell-like manner a portion of said boiler, for the air to be preheated; nest of tubes through which combustion gases pass arranged within said casing, the flue gases passing through the tubes effecting a heating of the air streaming along the outside of the tubes, and means for drawing the fresh air'through said casing and for forcing the heated air into the furnace to produce therein a pressure above atmospheric pressure.

In testimony that I claim the foregoing as my invention, I have signed my name.

HEINRICH BOLTSHAUS ER 

